JP4027303B2 - Rankine cycle equipment - Google Patents

Description

  The present invention relates to a Rankine cycle apparatus, and more particularly to a Rankine cycle apparatus used as an in-vehicle apparatus that converts, for example, exhaust heat energy of an in-vehicle engine into mechanical energy.

  Conventionally, a Rankine cycle apparatus is known as a system for converting thermal energy into mechanical work. The Rankine cycle apparatus has a structure in which water is circulated in a liquid phase state and a gas phase state in a sealed piping system that forms a circulation system. The Rankine cycle apparatus has a feed water pump unit, an evaporator, an expander, and a condenser, and forms a circulation circuit by piping connecting them.

  FIG. 19 shows a schematic configuration of the Rankine cycle apparatus. In FIG. 19, the on-board Rankine cycle device is assumed, the entire configuration is shown, and the structure and internal state of the condenser are shown in detail.

  In FIG. 19, the Rankine cycle apparatus includes a feed water pump unit 110, an evaporator 111, an expander 107, and a condenser 100. These elements are connected by pipes 108 and 115 to form a circulation circuit. The water (liquid phase) sent out at a predetermined amount per minute through the pipe 115 based on the water supply pump unit 110 is heated by the evaporator 111 and becomes water vapor (gas phase). This water vapor is sent to the expander 107 through the next pipe 115, where an expansion action occurs. Mechanical work is performed by driving a mechanical device (not shown) by the expansion action of water vapor in the expander 107. Thereafter, the water vapor whose temperature has been lowered and finished the expansion action is sent to the condenser 100 through the pipe 108, where it is returned from the water vapor state to the water state. Then, it returns to the feed water pump unit 110 through the piping 115, and is sent out from the feed water pump unit 110 again, and the above operation is repeated. In the above, the evaporator 111 is structured to receive heat from an exhaust pipe extending from the exhaust port of the engine. For example, Patent Document 1 can be cited as a document showing an example of the structure of the Rankine cycle device.

  Next, the structure and operation of the condenser 100 in the in-vehicle Rankine cycle device will be described in detail.

  The condenser 100 of the in-vehicle Rankine cycle device includes a water vapor introduction chamber 101, a water collection chamber 102, and a large number of cooling pipes 103 that connect these two chambers in the vertical direction. In FIG. 19, only one cooling pipe 103 is exaggerated. The upper half of the inside of the cooling pipe 103 is water vapor (gas phase portion) 104, and the lower half is water (liquid phase portion) 105. In the portion of the water vapor 104, most of the working medium introduced into the cooling pipe 103 from the water vapor introduction chamber 101 is in a gas phase. In the portion of the water 105, most of the working medium flowing through the cooling pipe 103 is in a liquid phase state (condensed water). The boundary between the water vapor 104 and the water 105 is the liquid surface position 112. A cooling fan 106 is provided behind the cooling pipe 103 (right side in FIG. 19) and driven. The periphery of the cooling fan 106 is surrounded by a shroud 106a. Usually, the operation of the cooling fan 106 is controlled by the electronic control unit based on the water temperature at the outlet of the condenser 100. The cooling pipe 103 is simultaneously blown and cooled by a single cooling fan 106 from its upper end to its lower end.

  The condenser 100 operates as follows. Relatively low temperature steam discharged from the expander 107 when the Rankine cycle apparatus is cooled down is introduced into the steam introduction chamber 101 of the condenser 100 through the low pressure steam pipe 108 and flows into the cooling pipe 103. . Cooling air 109 sucked by the cooling fan 106 is supplied to the condenser 100. Strong cooling air acts on the water vapor 104 upstream of the condenser 100, that is, the portion where water vapor and water are mixed in the cooling pipe 103, by the cooling fan 106, and the latent heat released when the water vapor is liquefied is the cooling air. Is effectively recovered. Cooling air from the cooling fan 106 also acts on the water 105 on the downstream side of the condenser 100, that is, the portion where only water is substantially present in the cooling pipe 103. Water condensed in the cooling pipe 103 of the condenser 100 is collected in the water collection chamber 102. Thereafter, as described above, the water is pressurized by the feed water pump unit 110 and supplied to the evaporator 111.

  When the high-temperature steam becomes abnormally high pressure due to some system abnormality in the on-vehicle Rankine cycle device as described above, it is necessary to quickly return from the abnormally high pressure state to the normal pressure state without impairing the functions of the surrounding equipment. is there.

Therefore, in Patent Document 2, a safety valve is provided on the pipe side through which water vapor passes. That is, in Patent Document 2, the evaporator discharge side and the condenser suction side are short-circuited at a branch line provided with a pressure safety valve, and when the internal pressure of the evaporator is high, water vapor is bypassed to the condenser. . Further, in Patent Document 3, a control valve for closing a circuit is provided between the condenser and the tank and at the outlet of the evaporator so as to prevent the expansion machine / condenser from being filled with liquid when no power is supplied and the operation is stopped. However, in the configuration described in Patent Document 2, it is difficult to control the high-pressure water vapor on the evaporator side because adjustment is performed only by a valve in a pipe through which steam passes. Moreover, since it is based on the control valve between a condenser and a tank in patent document 3, there exists a problem that a quick response at the time of emergency is difficult with respect to the pressure increase between a pump and an evaporator.
JP 2002-115504 A JP 49-92439 A Japanese Utility Model Publication No. 58-124603

  The problem of the present invention is that the allowable limit of the expander, evaporator, etc. in the circuit due to the flow of the working medium stagnant in any device such as the expander, evaporator, etc. that is located in the circuit of the Rankine cycle apparatus. When a high pressure exceeding the pressure is generated, not only the pressure is lowered quickly but also the high-temperature and high-pressure working medium is discharged out of the circuit in order to reduce the pressure so that each device can be maintained and restarted. The purpose is to lower the temperature of the medium itself and to reduce the influence of the exhaust working medium on peripheral devices such as an exhaust device. Further, the problem of the present invention is that it is difficult to reduce the pressure with a quick response in an emergency in response to a pressure increase exceeding the permissible limit pressure of water between the high-pressure water vapor on the evaporator side and the pump and the evaporator. It is to eliminate that.

  In view of the above-described problems, the object of the present invention is to promptly apply pressure in order to maintain and restart each device when a high pressure exceeding an allowable limit pressure such as an expander or an evaporator occurs in the circuit. In addition to lowering the pressure, when discharging the high-temperature and high-pressure working medium to the outside of the circuit to lower the pressure, the temperature of the working medium itself is lowered and the influence of the discharged working medium on peripheral devices such as exhaust devices is reduced. It is to provide a Rankine cycle device.

  The Rankine cycle device according to the present invention is configured as follows in order to achieve the above object.

First Rankine cycle device (corresponding to claim 1): The Rankine cycle device includes an evaporator that heats a liquid-phase working medium by heat from a heat source to change the phase to a gas-phase working medium, and a gas discharged from the evaporator. An expander that converts thermal energy of the phase working medium into mechanical energy, a condenser that cools the gas phase working medium discharged from the expander and returns it to the liquid phase working medium, and a liquid phase working medium discharged from the condenser. A supply pump for supplying pressure to the evaporator is provided in the closed circuit. In this Rankine cycle device, the internal pressure in the closed circuit is set at a pressure lower than the allowable limit pressure of the expander or the evaporator between the supply pump and the evaporator and the working medium is in a liquid phase state. A discharge valve device is provided for discharging the working medium to the outside of the closed circuit when the pressure is higher than the set limit pressure , and at least a part of the working medium discharged from the discharge valve device to the outside of the closed circuit is supplied to the heat source. Drain around.
Due to the above , the allowable limit pressure of the expander, evaporator, etc. in the circuit is exceeded due to the flow of the working medium in any device such as the expander, evaporator, etc. located and configured in the circuit of the Rankine cycle device When high pressure occurs, the discharge (relief) valve discharges the working medium to the outside of the circuit at the initial stage, and then discharges the liquid-phase working medium, and then drops the temperature of the gas-phase working medium (saturated steam) or condensed water. Since the maximum allowable pressure of expanders and evaporators in the closed circuit is not exceeded, maintenance and re-operation of each device is possible, and high-temperature and high-pressure working medium is discharged outside the closed circuit. In this case, the temperature of the working medium itself is decreased and the influence of the discharged working medium on peripheral devices such as an exhaust device can be reduced.
Furthermore, by cooling the evaporator heat source and the evaporator itself with the exhaust working medium, the temperature of the exhaust working medium to be discharged, particularly the gas phase working medium can be lowered, and a further lower pressure can be achieved. Furthermore, the influence on surrounding equipment can be reduced, and overheating due to overheating of the heat source (such as the engine exhaust passage) and the evaporator can be prevented.

In the second Rankine cycle device (corresponding to claim 2), in each of the above configurations, the discharge valve device preferably discharges the discharged working medium to the outside of the closed circuit and discharges it to the outside of the closed circuit. And a flow restriction device is provided in at least a part of the discharge passage. As a result, the discharge flow rate can be adjusted by a flow control device (orifice, etc.), so that the degree of influence due to discharge to surrounding equipment can be adjusted, and in particular, a high-temperature heat source (engine exhaust passage and its surroundings). ) And the cooling rate of the evaporator, etc., as a discharge flow rate that suppresses thermal shock that does not become sudden and rapid cooling, enabling proper cooling that enables maintenance and re-operation.

In the third Rankine cycle device (corresponding to claim 3), in each of the above configurations, the discharge valve device is preferably arranged at least closer to the supply pump side than the evaporator. As a result, it becomes far from the evaporator, so that a large amount of water can be secured in the piping, so that the discharge amount of the liquid phase working medium in the initial stage can be increased, and the temperature reduction and pressure reduction of the discharged gas phase working medium is further promoted thereafter. The pressure can be reduced, the discharge pressure (flow rate) can be reduced, and the influence on surrounding equipment can be reduced.

A fourth Rankine cycle device (corresponding to claim 4) includes an evaporator that heats a liquid-phase working medium by heat from a heat source to change the phase to a gas-phase working medium, and a gas-phase working medium discharged from the evaporator. An expander that converts thermal energy into mechanical energy, a condenser that cools the gas phase working medium discharged from the expander and changes the phase to a liquid phase working medium, and pressurizes the liquid phase working medium discharged from the condenser In a Rankine cycle device having a supply pump for supplying to an evaporator in a closed circuit, the internal pressure in the closed circuit is between the supply pump and the evaporator and the working medium is in a liquid phase state. A discharge valve device that opens the closed circuit to the atmosphere and discharges the working medium in the circuit out of the closed circuit when the pressure is higher than the set limit pressure set lower than the allowable limit pressure of the expander or the evaporator. At least than the evaporator Close to the side of the pump, characterized in that disposed.
In the fifth Rankine cycle device (corresponding to claim 5), the discharge valve device preferably has a discharge passage for leading the discharged working medium out of the closed circuit and discharging it out of the closed circuit. A plurality of flow rate limiting devices are provided in at least a part of the discharge passage.

  According to the present invention, the allowable limit of the expander, the evaporator, etc. in the circuit due to the flow of the working medium in any of the expander, the evaporator, etc. located and configured in the circuit of the Rankine cycle apparatus. When a high pressure exceeding the pressure occurs, the discharge (relief) valve causes the working medium to be discharged to the outside of the circuit at the initial stage, and then the liquid-phase working medium is discharged. Or condensate will be discharged, and the allowable limit pressure of expanders and evaporators in the closed circuit will not be exceeded, so that each device can be maintained and restarted, and a high-temperature and high-pressure working medium can be installed outside the road. When discharging, the temperature of the working medium itself is lowered and the influence of the discharged working medium on peripheral devices such as an exhaust device can be reduced. In addition, the pressure can be lowered with a quick response in an emergency in response to a high pressure water vapor on the evaporator side or a pressure increase exceeding the sudden allowable limit pressure of water between the pump and the evaporator.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments (examples) of the invention will be described with reference to the accompanying drawings.

  First, the configuration of the entire system of the Rankine cycle device according to the present invention will be described with reference to FIG.

  The Rankine cycle apparatus 10 includes an evaporator 11, an expander 12, a condenser 13, and a feed water pump unit 14 including a supply pump. The evaporator 11 is connected to the expander 12 by a pipe 15, the expander 12 is connected to the condenser 13 by a pipe 16, the condenser 13 is connected to the feed water pump unit 14 by a pipe 17, and the feed water pump unit 14 is connected. Is connected to the evaporator 11 by a pipe 18. With such a piping structure, a circulation circuit in which the working medium circulates in the Rankine cycle apparatus 10 is formed. In the Rankine cycle device 10, the working medium is water or steam.

  The circulation circuit of the Rankine cycle apparatus 10 has a circulation structure sealed against the outside where water or water vapor is circulated. In the circulation circuit of the Rankine cycle apparatus 10, water (liquid phase) moves from the liquid surface position indicated by the broken line P <b> 1 in the condenser 13 to the evaporator 11 through the water supply pump unit 14. In FIG. 1, the pipes 17 and 18 related to the water portion are represented by thick solid lines. Further, water vapor (vapor phase) moves from the evaporator 11 through the expander 12 to the liquid level position P1 of the condenser 13. In FIG. 1, the pipes 15 and 16 relating to the water vapor portion are represented by thick broken lines.

  Further, the pipe 18 between the supply pump unit 14 and the evaporator 11, which is a low temperature region of the Rankine cycle apparatus 10, is provided with branch pipes 200 and 201, and a first relief valve 22 and a second relief valve 202 are provided. In a circuit in which the working medium is in a liquid phase state, a discharge (relief) valve device 203 is provided to discharge the working medium to the outside of the circuit when the internal pressure in the circuit is higher than the set limit pressure. At least a part of the working medium discharged from the discharge valve device 203 to the outside of the closed circuit is discharged around the heat source (exhaust pipe 45) of the Rankine cycle device 10 in a low-temperature liquid phase. The discharge valve device 203 includes a plurality of discharge passages (pipes 204, 205, 206, 207, 208) for leading the discharge working medium out of the closed circuit and discharging it out of the closed circuit, and at least a part of the discharge passage. Is provided with a flow restriction device (orifice) 209. Further, the discharge valve device 203 is disposed closer to the supply pump 44 side than at least the evaporator 11. In addition, although the discharge valve is provided in two places, the 1st relief valve 22 and the 2nd relief valve 203 here, you may make it provide only one.

  The Rankine cycle apparatus 10 changes the phase of water to water vapor using heat discharged from a heat source, and generates mechanical work using the expansion action of water vapor. The evaporator 11 is a mechanism for changing the phase of water to water vapor. As will be described later, the Rankine cycle device 10 according to this embodiment is configured as an in-vehicle device mounted on an automobile. For this reason, the evaporator 11 uses the heat of the exhaust gas as a heat source. That is, the evaporator 11 uses the heat of the exhaust gas passing through the exhaust pipe 45 of the engine (internal combustion engine) to heat the water supplied from the feed water pump unit 14 and further overheat to raise the temperature and pressure. Generate high-pressure steam. The high-temperature and high-pressure steam generated in the evaporator 11 is supplied to the expander 12. Needless to say, irrespective of the exhaust pipe 45, the heat of the exhaust gas having a higher temperature such as an exhaust port downstream from the exhaust valve of the engine or an exhaust manifold (not shown) can be used.

  In the expander 12, the output shaft 12a is connected to a rotor or the like (not shown) of a motor / generator (M / G) 19 and is driven as a generator. The expander 12 has a structure for expanding the high-temperature and high-pressure steam supplied from the evaporator 11, and rotates the output shaft 12a based on the expansion action of the steam. When the output shaft 12a of the expander 12 rotates, the rotor of the motor / generator 19 is rotated to perform a required mechanical rotation operation or power generation operation. Thereby, mechanical work can be performed using the heat of exhaust gas. The output shaft 12a of the expander 12 is also connected to the hydraulic pump 25 to drive it.

  As described above, the expander 12 outputs mechanical work by the expansion action of the high-temperature and high-pressure steam supplied from the evaporator 11 through the pipe 15 to drive each load such as the motor / generator 19 and the hydraulic pump 25. . The water vapor discharged from the expander 12 and lowered in temperature and temperature decreases in temperature and pressure, and is supplied to the condenser 13 via the pipe 16 in this state. The condenser 13 cools and liquefies the water vapor from the expander 12. Water (condensed water) generated by liquefaction in the condenser 13 is returned to the feed water pump unit 14 via the pipe 17. The high-pressure feed water pump 44 of the feed water pump unit 14 pressurizes the condensed water liquefied by the condenser 13 and supplies the condensed water again to the evaporator 11 through the pipe 18.

  The Rankine cycle apparatus 10 having the entire system configuration as described above includes the following elements as other related components.

  The casing 21 of the expander 12 is provided with a breather (separator) 23 for returning leaked water vapor to the pipe 16. An oil sump 24 is provided at the lower part of the expander 12, and oil mixed with water from the oil sump 24 is passed through a pipe 26 by an oil pump 25 through an oil coalescer 27. Water and oil are separated by the oil coalescer 27, and the water is accommodated in the lower part of the oil tank 28 due to the difference in specific gravity. A valve mechanism 30 that is operated by a float sensor 29 is attached to the oil tank 28. The oil stored in the upper part of the oil tank 28 separated by the oil coalescer 27 is supplied to each part of the expander 12 through the pipe 31 and via an oil passage (not shown) formed in the output shaft 12a. . The water stored in the lower portion of the oil tank 28 is supplied through the pipe 33 to the open tank 32 of the water supply pump unit 14 by the operation of the valve mechanism 30. A pipe 35 to the condenser 13 is provided from the open tank 32 of the feed water pump unit 14 via a check valve 34. The condenser 13 is provided with a liquid level sensor 38 and an air vent 39 in the vicinity of the liquid level position. Water supply from the open tank 32 to the condenser 13 is performed by a return pump 37 driven by a motor 36 that is turned on and off by a signal from a liquid level sensor 38. Further, the condenser 13 is provided with a pipe 40 for draining to the open tank 32 through the air vent 39. The pipe 17 for returning the condensed water discharged from the condenser 13 is connected to a water coalescer 42 in the sealed tank 41 of the water supply pump unit 14. The water in the sealed tank 41 is supplied to the evaporator 11 through the pipe 18 by a high-pressure feed water pump 44 operated by a motor 43. Furthermore, the condenser 13 is provided with a plurality of cooling fans 46, 47, and 48 for generating cooling air independently depending on the location.

  In the above configuration, the working medium supply device is configured by the device portion related to the lower portion from the liquid level position inside the condenser 13 and the feed water pump unit 14. In the circulating system of the sealed working medium in the Rankine cycle device 10, the working medium leaked from the breather 23 of the expander 12 is returned to the pipe 16 via the outlet P2, and returned to the circulating system.

  FIG. 2 is a configuration diagram showing a specific structure of the water supply pump unit 14 described above. The water supply pump unit 14 includes a water coalescer 42, a sealed tank 41, a high-pressure water supply pump 44 operated by a drive motor 43, an open tank 32, a return pump 37, and a check valve 34. In FIG. 2, the rotation shaft 49 of the drive motor 43 is shown in parallel with the paper surface. However, this is for convenience of explanation, and in actuality, the rotation shaft 49 is arranged so as to be perpendicular to the paper surface. Yes. A cam mechanism 49a is engaged with the rotation shaft 49 of the drive motor 43 to form a cam shaft.

  In the above, the water coalescer 42 performs oil separation. The sealed tank 41 directly collects leaked water from the high-pressure feed pump 44. The high-pressure feed water pump 44 supplies the required amount of water by controlling it according to the pump speed. The open tank 32 is for temporarily storing leaked water outside the system. The return pump 37 returns the leaked water to the sealed tank 41 or returns the water to the subcooler of the condenser 13. That is, the return pump 37 returns the leaked water from the open tank 32 to the sealed tank 41 through the pipe 152 provided with the check valve 151, and supercools the condenser 13 through the pipe 35 provided with the check valve 34 as necessary. Send water to the vessel. The check valve 151 in the pipe 152 prevents a back flow from the sealed tank 41, and the check valve 34 in the pipe 35 prevents a back flow from the subcooler of the condenser 13. Water from the outlet 13 a of the condenser 13 enters the high-pressure feed water pump 44 driven by the drive motor 43 through the pipe 17. The high-pressure feed pump 44 sends water to the evaporator 11 through the pipe 18. In addition, leaked water is returned to the open tank 32 by the pipe 40.

  Next, the discharge valve device 203 will be described. In the discharge valve device 203, the first relief valve 22 is provided at an intermediate position between the discharge port of the high-pressure pump 44 and the inlet of the evaporator 11. First, the pressure is reduced by discharging in a water state, and then the reverse flow is caused from the evaporator. Vapor is released at low pressure. The relief circuit may (1) guide the drainage destination with the pipe 204 into the exhaust pipe 45 downstream of the evaporator 11, and (2) guide the pipe with the pipe 205 upstream of the evaporator 11. When the first relief valve 22 is activated, the system needs to be shut down urgently. Therefore, the first relief valve 22 is provided at an intermediate position between the discharge port of the high-pressure pump 44 and the inlet of the evaporator 11. First, relief is performed in the water state during the initial high pressure, and after that, the pressure is reduced and then flows back from the evaporator 11. Vapor is released. Therefore, the branching position of the relief circuit is not so close to the evaporator 11, and the distance to the exhaust pipe 45 is close to the discharge port of the high-pressure feed water pump 44 so that a sufficient amount of working medium can be discharged in the water state. A position as short as possible is good. When the 1st relief valve 22 act | operates, a flow will stop instantaneously inside a heat exchanger tube, and it will start a backflow continuously. For this reason, if the exhaust gas heat flow rate is large, there is a risk of overheating of the heat transfer tube. For this reason, there are the following two methods depending on the return destination of the relief circuit.

(1) In the case of discharging to the heat source (exhaust pipe 45 / evaporator 11), since the guide destination of the relief circuit is upstream of the evaporator 11, a large flow rate of the working medium is instantaneously injected toward the evaporator 11. However, if the injection amount is too large, the heat transfer tube and the evaporator 11 housing member are rapidly cooled, and there is a concern about deterioration due to thermal shock. Accordingly, by setting the orifice 209 or the like in the relief circuit in advance so that the optimum injection amount according to the heat capacity of the evaporator 11 is set, the pressure drop rate of the high pressure circuit is somewhat hindered, but the heat transfer tube is rapidly cooled. In addition, there is an effect that the engine output state can be gradually reduced while avoiding secondary damage due to excessive temperature rise. Furthermore, cooling the heat source (exhaust pipe 45 / evaporator 11) means cooling the heat source (exhaust pipe 45) that generates high-temperature and high-pressure steam in the evaporator 11 and the generated high-temperature and high-pressure steam in the evaporator 11. As a result, the vapor of the discharged working medium can be further reduced in temperature and pressure.

(2) In the case of discharging to the exhaust pipe 45 (downstream of the evaporator 11), when guided to the downstream of the evaporator 11, there is no need to provide a flow rate adjusting mechanism such as an orifice 209 to the relief circuit. This is the simplest method, and the pressure in the high-pressure circuit can be lowered more quickly than in (1). However, when the safety valve is activated during a high heat load or the like, the evaporator 11 temporarily becomes empty and secondary damage to the heat transfer tube due to excessive temperature rise is a concern. It is necessary to prevent an excessive amount of heat from entering the evaporator 11 by control such as limiting to the above.

  Next, with reference to FIG. 3, the structural example when said Rankine-cycle apparatus 10 is mounted in a vehicle is demonstrated.

  Reference numeral 301 denotes a contour of the body shape at the front of the vehicle, and reference numeral 302 denotes a front wheel. The interior of the body 301 is an engine room 303, and the engine 50 is mounted in the engine room 303. An exhaust manifold 51 is provided on the back side of the engine 50, and the exhaust pipe 45 described above is connected to the exhaust manifold 51. The evaporator 11 is provided at a location near the exhaust manifold 51 in the exhaust pipe 45. A pipe 18 from the high-pressure feed pump 44 is connected to the evaporator 11. The pipe 18 supplies water to the evaporator 11 using the heat of the exhaust gas discharged from the exhaust manifold 51 as a heat source. The evaporator 11 phase-converts water into steam with the heat of the exhaust gas, and supplies the steam to the expander 12 through a pipe 15 connected to the steam inlet 52 of the expander 12. The expander 12 converts the expansion energy of water vapor into mechanical energy.

  The water vapor outlet 53 of the expander 12 is connected to the pipe 16. A condenser 13 that cools and condenses water vapor to form a liquid is disposed between the pipe 16 and the sealed tank 41 that leads to the inlet side of the high-pressure feed water pump 44. The condenser 13 is located in front of the front part of the vehicle. FIG. 3 shows the layout of the open tank 32, the water coalescer 42, the return pump 37, the oil coalescer 27, the supercooler (liquid phase part of the condenser 13) 54, the air vent 39, the check valve 34, and the like. Has been.

  In the pipe 18, a safety valve 22 is attached to the branch pipe 200, a pipe 204 is connected from the safety valve 22, and an exhaust port thereof is provided toward the exhaust pipe 45. Further, an orifice 209 may be provided by a pipe 205 as indicated by a dotted line and discharged to the upstream side of the evaporator 11.

  The high-pressure feed water pump 44, the evaporator 11, the expander 12, the condenser 13 and the like constitute a Rankine cycle device that converts thermal energy into mechanical energy as described above.

  Next, the operation of the Rankine cycle device will be described along the flow of water and water vapor.

  The water cooled and condensed by the condenser 13 is pressurized by the high-pressure feed water pump 44 and supplied to the evaporator 11 through the pipe 18.

  Water, which is a liquid phase working medium, is heated by adding heat energy in the evaporator 11, further heated to high temperature / high pressure steam that has been heated and pressurized, and is supplied to the expander 12. The expander 12 converts thermal energy into mechanical energy by the expansion action of the high-temperature and high-pressure steam whose temperature has been increased. Thereby, the motor / generator 19 attached to the expander 12 obtains mechanical energy.

  The water vapor that has flowed out of the expander 12 becomes water vapor whose temperature has been lowered and reduced, and flows into the condenser 13. The temperature-decreased water vapor that has flowed into the condenser 13 is cooled and condensed again, and is then supplied to the high-pressure feed pump 44 through the water coalescer 42 as condensed water. Thereafter, the water that is the working medium repeats the above circulation, and continues to supply the high-temperature and high-pressure water vapor that has been heated and pressurized to the expander 12.

  Next, the setting of the second relief valve 202 and the first relief valve 22 of the discharge valve device 203 will be described. 4 is a graph of the time change of the exhaust gas energy, FIG. 5 is a graph of the time change of the target water supply amount, and FIG. 6 is a graph of the time change of the steam pressure. The horizontal axis of FIGS. 4-6 shows time, and the time axis of all the figures is common. In FIG. 4, the exhaust gas energy changes as the vehicle starts and stops, and the steam pressure changes as indicated by curves P1, P2, and P3 as the exhaust gas energy and the target water supply amount change. Moreover, the straight line L10 of FIG. 6 shows the allowable limit pressure of the expander or the evaporator. Therefore, the operating pressure of the safety valve is set higher than the normal steam pressure as shown by the straight lines C11 and C12.

  When the second relief valve 202 is used alone, its operating pressure is set to about twice the operating pressure (first operating limit pressure). Accordingly, only the excess pressure is reduced while maintaining the system operating pressure, so that the operation of Rankine can be maintained. The relief circuit includes a method of connecting to the exhaust pipe by a pipe 207 and a method of connecting to an open tank by a pipe 208. In the latter case, the working medium can be recovered and regenerated.

  When the first relief valve 22 is used alone, its operating pressure is set to about 2.5 times the second operating pressure (second operating limit pressure). As a result, the pressure is always released below the allowable limit pressure close to the pressure limit, so that the evaporator and the expander are reliably maintained, and the system can be restarted after replacing the rupture disc of the safety valve.

  When using together the 1st relief valve 22 and the 2nd relief valve 208, the operating pressure of each valve is set similarly to 1 and 2. As a result, it is possible to take a fail-safe against a malfunction of the relief valve.

  FIG. 7 is a longitudinal sectional view of the second relief valve 202. In the relief valve, a valve body 401, a valve body support portion 402 screwed to the valve body, and a cap 403 covering the valve body support portion 402 are coupled by a screw mechanism, and can be moved up and down by an O-ring 404 and a seal 405. A shaft-like valve body 406 is elastically supported and fixed by a spring 407 provided on the upper portion. When the pressure at the piping port 408 becomes higher than the set value, the end of the shaft-like valve body 406 pushes the spring 407 by the pressure, and a gap is formed between the O-ring 404 and the shaft 406 so that the leak occurs from the gap. It has become.

  FIG. 8 shows a bursting safety valve as an example of the first relief valve 22. A rupture plate 413 supported by a backup ring 412 is fixed in the holder A, which includes a holder A410 and a holder B411. As shown in FIGS. 9 (a) and 9 (b), the rupturable plate 413 is configured such that when a predetermined pressure is applied, the disk portion 414 is opened as shown in FIG. 9 (b). When a predetermined pressure abnormality occurs, it will leak.

  Next, with reference to FIGS. 10-18, control of the liquid level position of the water stored in the condenser 13 in the Rankine cycle apparatus 10 will be described.

  FIG. 10 illustrates the Rankine cycle apparatus 10 system with the condenser 13 as the center, and the condenser 13 is illustrated as a front view seen from the front side of the vehicle. FIG. 10 shows the state of the working medium inside the condenser 13 (water (or condensed water): W1, water vapor: W2). FIG. 5 is a side view of the condenser showing the positional relationship of the cooling fans 46, 47, and 48 in the condenser 13, and the internal state is also shown.

  The condenser 13 includes a water vapor introducing chamber 13A at the upper end, a water collecting chamber 13B at the lower end, and an intermediate chamber 56 at the center. A plurality of cooling pipes 55 are provided between the water vapor introducing chamber 13A and the intermediate chamber 56, and between the intermediate chamber 56 and the water collecting chamber 13B, and the respective chambers are in communication with each other. Cooling fins 55 a are provided around the cooling pipe 55.

  The water vapor introduction chamber 13 </ b> A of the condenser 13 is connected to the water vapor outlet 53 of the expander 12 through the pipe 16. The water collection chamber 13B of the condenser 13 is connected to the water supply pump unit 14 via a pipe 17 and the like. As described above, the expander 12 is connected to the evaporator 11 via the pipe 15, and similarly, the feed water pump unit 14 is connected to the evaporator 11 via the pipe 18. The evaporator 11 receives heat 50 </ b> A from the exhaust gas of the engine (heat source) 50 through the exhaust pipe 45. In the water supply pump unit 14, components such as the sealed tank 41, the water coalescer 42, the high-pressure water supply pump 44, the drive motor 43, the open tank 32, the return pump 37, and the motor 36 are shown.

  In the condenser 13, the water vapor W <b> 2 is cooled and condensed to become water (condensed water) W <b> 1 and stored in the lower side of the water. The horizontal line shown in the intermediate chamber 56 indicates the liquid level 65 (corresponding to the liquid level position P1 in FIG. 1), and indicates the position of the liquid level of the water W1 stored in the condenser 13. A liquid level sensor 38 and an intermediate drain port 59 are provided at required positions corresponding to the position of the liquid level 65 in the intermediate chamber 56. A detection signal related to the liquid level position output from the liquid level sensor 38 is sent to the control device 60. The control device 60 generates a motor control command signal based on the liquid level position detection signal, and gives this motor control command signal to the motor 36 of the return pump 37. On the other hand, an air vent 39 for water vapor is connected to the intermediate drain 59. The outlet side of the air vent 39 communicates with the open tank 32 via a pipe 40 having a check valve 58. An exhaust pump 57 is attached to the pipe 40 in parallel.

  Further, in the condenser 13, as shown in FIG. 11, a cooling fan 46 is disposed on the back side corresponding to the area where the water vapor W2 exists, and the cooling fan 47, corresponding to the area where the water W1 exists. 48 is arranged. The cooling operation of the cooling fan 46 is controlled by the pressure control device 62 based on, for example, a water vapor pressure detection signal of a pressure sensor 61 attached to the pipe 16 to which the water vapor W2 is supplied. The cooling fan 46 is a condensing cooling fan used for water vapor pressure adjustment. The cooling operation of the cooling fans 47 and 48 is controlled by the temperature control device 64 based on, for example, a water temperature detection signal of the temperature sensor 63 attached to the pipe 17 through which the water W1 flows. The cooling fans 47 and 48 are water cooling cooling fans for cooling the condensed water. In FIG. 11, A <b> 1 indicates the flow of cooling air from the front based on the rotation operation of the cooling fan 46, and A <b> 2 indicates the flow of cooling air from the front based on the rotation operation of the cooling fans 47 and 48. As described above, in the condenser 13, the cooling of the gas phase part (steam condensing part) 70, which is an equipment part corresponding to the water vapor W2, and the liquid phase part (condensed water cooling part), which is an equipment part corresponding to the water W1. The cooling of 71 is performed independently. Reference numeral 72 denotes a shroud that partitions each independent cooling region.

  In the above configuration, the water vapor coming out of the water vapor outlet 53 of the expander 12 is equivalent to atmospheric pressure. In the intermediate chamber 56 which is an outlet collection portion of each of the upper cooling pipes (condensation pipes) 55, water is discharged from the air vent 39 in order to adjust the liquid level 65 to be located in this space. The high-pressure feed water pump 44 serves as a feed pump for the main circulation circuit of the Rankine cycle apparatus 10 and sends a required amount of water to the evaporator 11.

  Further, in the above configuration, the reserve open tank 32 is open to the atmosphere, and reserve water is reserved for reserve in a closed circulation circuit in the system. The return pump 37 receives the signal from the liquid level sensor 38 and supplies water into the condenser 13. The exhaust pump 57 sucks the downstream side of the air vent 39 when the condenser 13 is operated at a negative pressure.

  Note that the operation of the exhaust pump 57 is performed by sensing the negative pressure with the pressure sensor 61 and the pressure control device 62 shown in FIG. 11, or the liquid level 65 is detected by the liquid level sensor 38. It can be configured to sense when the position exceeds the upper limit of the predetermined range and operate by the control device 60.

  Further, the check valve 58 prevents the backflow of the atmosphere when the inside of the condenser 13 becomes a negative pressure. The check valve 34 prevents a back flow of the return pump 37. The water vapor air vent 39 allows water and air to pass but does not pass water vapor. The intermediate drain port 59 is for restricting the change in the position of the liquid level 65 of the condensed water due to discharge of noncondensable gas and overflow of the water so that the liquid level position varies within a predetermined range. The liquid level sensor 38 outputs a position signal related to the liquid level 65 to the control device 60. The control device 60 controls the operation of the return pump 37 so that the position of the liquid level 65 exists in the intermediate chamber 56. The position of the liquid level 65 is controlled to be a height position included in a range between the air vent 39 and the liquid level sensor 38. For the liquid level sensor 38, for example, a capacitance type level sensor or a float type level switch is used.

  The pressure sensor 61 detects the pressure inside the condenser 13, and basically detects the pressure of the water vapor W2. The pressure control device 62 operates the cooling fan 46 so that the internal pressure of the condenser 13 becomes a set value. The temperature sensor 63 detects the temperature of the condensed water W1. The temperature control device 64 operates the cooling fans 47 and 48 so that the condensed water temperature becomes a set value.

  The structure and operation of the air vent 39 will be described in detail with reference to FIGS. 12 and 13 show a state in which the air vent 39 is closed, FIG. 12 is a longitudinal sectional view, and FIG. 13 is a sectional view taken along line AA in FIG. FIG. 14 is a longitudinal sectional view showing a state when the air vent is open. In FIG. 12 and the like, the left side of the air vent 39 is the condenser side, and the right side is the atmosphere side. The air vent 39 is sealed when the interior is filled with saturated water vapor (FIG. 12), and is automatically opened when non-condensable gas such as water or air is present to discharge water or non-condensable gas. Seal again (FIG. 14).

  The air vent 39 includes a valve 66 disposed at a central position of the container, a valve support 67 that supports the valve 66, and a valve opening (packing) 68. The valve 66 supported by the valve support 67 is arranged in a positional relationship capable of closing the valve port 68. The valve 66 is formed by combining two diaphragms 66a so as to form a sealed space, and a thermo liquid (temperature sensitive liquid) 69 is accommodated in the sealed space inside. The thermo liquid 69 has a characteristic that, like water, it is liquid under a certain pressure and below a certain temperature and expands as a gas when exceeding a certain temperature. FIG. 15 shows a saturation curve C1 of thermolyd and a saturation curve C2 of water. Since the temperature at which the thermo liquid 69 becomes gas is lower than the temperature at which water becomes steam by ΔT (about 10 ° C.), the thermo liquid 69 is vaporized and vaporized when the inside of the air vent 39 is an atmosphere of water vapor W2. Thus, the sealed space containing the expanded thermo liquid 69 pushes the diaphragms 66a on both sides outward, and closes the gap between the valve 66 and the valve port 68 formed by the diaphragm 66a (FIG. 12). Conversely, when the inside is at a low temperature (the surrounding environment is a non-condensable gas A3 such as air), the thermo liquid 69 is in a liquid state, the diaphragm 66a contracts inward, and the valve 66 and the valve port Air or the like is discharged from the gaps 68 (FIG. 14).

  In the above configuration, the control device 60 controls the position of the liquid surface 65 in the condenser 13 that is cooled by the cooling fan 46 and returns the water vapor W2 to the water (condensed water) W1 so as to change within a predetermined range. It is a control device. Based on the detection signal from the liquid level sensor 38 that detects the position of the liquid level 65 that is the boundary between the gas phase part 70 and the liquid phase part 71 in the condenser 13, the control device 60 is lower than the lower limit of the predetermined range. When it drops, the operation of the motor 36 of the return pump 37 that supplies water into the condenser 13 is controlled, and the insufficient amount of water is replenished from the open tank 32 through the pipe 35. Further, when the position of the liquid surface 65 of the liquid phase portion 71 exceeds the upper limit of the predetermined range, the excess water is discharged to the open tank 32 by the intermediate drain 59 and the air vent 39 and the like. Thus, a desirable predetermined range of the position of the liquid level 65 is set by a range determined by the lower limit based on the liquid level sensor 38 and the upper limit based on the air vent 39.

  This will be described in more detail. An intermediate drain port 59 for draining water (condensed water) W1 is installed in the intermediate chamber 56 of the condenser 13 to regulate the upper limit position of the liquid level 65. When the liquid level 65 rises above the intermediate drainage port 59, the position of the liquid level 65 is lowered by causing water to overflow from the intermediate drainage port 59 to the reserve open tank 32. When the liquid level 65 is located below the intermediate drainage port 59, an air vent 39 is installed at the intermediate drainage port 59 so that water vapor is not discharged from the intermediate drainage port 59. As shown in FIGS. 12 to 14, the air vent 39 for preventing the discharge of water vapor is automatically closed when water vapor is present inside, and air (non-condensable gas) or water is present inside. Sometimes the valve opens automatically. Further, a liquid level sensor 38 is disposed at a position below the intermediate drain 59, and when the position of the liquid level 65 is lower than the liquid level sensor 38, water is supplied from the open tank 32 by the return pump 37 and the liquid level 65 is supplied. Is raised to the position of the liquid level sensor 38. Based on the above action, the position of the liquid level 65 is always maintained within the range between the intermediate drain 59 and the liquid level sensor 38. When the interval between the intermediate drain 59 and the liquid level sensor 38 is increased, the error in the heat transfer area between the water vapor W2 side and the water (condensed water) W1 side increases. On the contrary, when the interval becomes small, the operations of the return pump 37 and the air vent 39 frequently occur. Therefore, the distance between the intermediate drain 59 and the liquid level sensor 38 may be set within a range where both of these two effects are reduced. Furthermore, if the main point is to make the heat transfer area constant, the interval is infinitely small and is preferably zero.

  FIG. 16 shows details of the position setting of the liquid level 65. 16A shows the positional relationship among the liquid level sensor 38, the air vent 39, and the liquid level 65, and FIG. 16B shows the relationship between the liquid level position, the operation of the air vent, and the operation of the return pump. .

In FIG. 16A, H _A is set as the upper limit liquid level position, H _B is set as the lower limit liquid level position, and _HL is set as the liquid level position 65. When the position _HL of the liquid level 65 is higher than the upper limit liquid level position _HA , the air vent 39 is in an open state and the return pump 37 is off (OFF). Position H _L of the liquid level 65, when located between the upper liquid surface position H _A and the lower limit liquid level position H _B is the air vent 39 is closed, the return pump 37 is off. When the position _{H L} of the liquid level 65 is lower than the lower limit liquid level position _{H B} is the air vent 39 is closed, the return pump 37 is turned on (ON). Thus, variation of the liquid level 65 is suppressed to the upper limit liquid level position in the range of H _A and the lower limit liquid level position H _B.

  In addition, when the Rankine cycle apparatus 10 is started / stopped or transiently changed, the amount of water vapor (mass flow rate) or the amount of drainage (mass flow rate) from the condenser 13 to the high-pressure feed water pump 44 changes. The fluctuation | variation of the position of the liquid level 65 inside can be suppressed, and the operation | movement of the condenser 13 can be performed stably.

  Further, as shown in FIG. 10, a reserve release tank 32 that is open to the atmosphere is provided separately from the sealed main circuit of the Rankine cycle apparatus 10. The open tank 32 is connected to the condenser 13 through an air vent 39 connected to the intermediate drain 59 and a check valve 58. The lower part of the open tank 32 is connected to the outlet 13 a of the condenser 13 via a return pump 37, a pipe 35 and a check valve 34. When the liquid level 65 is higher than the intermediate drain 59, the water overflows into the open tank 32, and when the liquid level 65 is lower than the liquid level sensor 38, the return pump 37 is operated to replenish the water. Since the water supply amount of the high-pressure feed pump 44 located downstream of the condenser 13 is controlled, when the return pump 37 is activated, the liquid level 65 rises due to the water supply into the condenser 13 and the position of the liquid level sensor 38. Thus, the return pump 37 stops. Further, since an intermediate chamber 56 is provided in a region including the intermediate drain port 59 and the liquid level sensor 38 and a plurality of cooling pipes (condensation pipes) 55 are gathered, the drain pump 59 or the return pump 37 is drained from the intermediate drain port 59. It is possible to improve and stabilize the responsiveness of the change in the liquid level 65 when water is supplied. In addition, it is only necessary that each cooling pipe (condensation pipe) 55 communicates with the intermediate chamber 56 portion on the water vapor introducing chamber 13A side and the water collecting chamber 13B side, and the provision of the intermediate chamber 56 is not essential.

  Next, the flow of the liquid surface position control performed in the control device 60 will be described with reference to the flowchart of FIG.

First, the position _HL of the liquid level 65 is read by the liquid level sensor 38 (step S10). It is determined whether or not the liquid level position H _L is higher than the upper limit liquid level position H _A (step S11). If the liquid level position H _L is higher than the upper limit liquid level position _HA , the air vent 39 is opened and drained, and the liquid level 65 is lowered (step S12). Thereafter, the process returns to step S10 and returns to step S10. If the liquid level position _HL is equal to or lower than the upper limit liquid level position _HA , the air vent 39 is closed (step S13). The next step, whether the liquid surface position H _L is lower than the lower limit liquid level position H _B is determined (step S14). If and when the liquid level position H _L is lower than the lower limit liquid level position H _B is the return pump 37 is turned on, water is supplied (step S15). If and when the liquid level position H _L is equal to or greater than the lower limit liquid level position H _B is the return pump 37 is turned off, supply of water is not performed (step S16). Thereafter, the process returns to step S10 and returns to step S10.

  FIG. 18 is a timing chart showing changes in vehicle speed, engine output, feed water flow rate to the evaporator, and change in the liquid level position of the condenser in comparison with the conventional device, in a vehicle equipped with the Rankine cycle device 10 according to the present embodiment. It is a chart. 18A shows the change in the vehicle speed, FIG. 18B shows the change in the engine output, FIG. 18C shows the change in the evaporator feed water flow rate in the conventional apparatus, and FIG. 18D shows the liquid level position in the condenser of the conventional apparatus. Each change is shown. In FIG. 13, the horizontal axis represents time. When the vehicle on which the Rankine cycle device is mounted changes the vehicle speed as shown in FIG. 18 (A), the engine output changes as shown in FIG. 18 (B), and as shown in FIG. 18 (C). Thus, a change in the feed water flow rate to the evaporator occurs, and the liquid level position of the condenser changes as shown in FIG. In other words, on the lateral time axis, when the vehicle starts at times t1, t3, and t5 and stops at times t2, t4, and t6, the engine output changes as the vehicle starts and stops, evaporating The feed water flow rate to the condenser also changes, and the liquid level position of the condenser fluctuates.

  As described above, in the on-vehicle Rankine cycle condenser 100, as shown in FIG. 18 (A), when the vehicle starts / stops or when the vehicle speed changes transiently, the engine output as shown in FIG. 18 (B). Therefore, the feed water flow rate to the evaporator 111 changes, and the liquid level position 112 in the cooling pipe 103 of the condenser 100 changes. That is, in the condenser 100, when the inflow amount of water vapor is larger than the drainage amount of condensed water, the liquid level position 112 rises, and when the inflow amount of water vapor is less than the drainage amount of condensed water, the liquid level position 112 decreases. It will be.

As opposed to the above, according to the configuration of the present embodiment, when the vehicle changes the vehicle speed as shown in FIG. 18A, the liquid level position is controlled as described above. and at the time when the starting and stopping only variation between the upper limit position H _a and the lower limit position H _B, large variation does not occur.

  As described above, by suppressing the position fluctuation of the liquid level 65 of the water (condensed water) W1 stored in the condenser 13 to a predetermined range, the vapor phase portion corresponding to the water vapor in the condenser 13 and the condensed water are reduced. Cavitation in the pump device and the evaporator can be reduced by reducing the change in the heat transfer area of the corresponding liquid phase part, allowing cooling without considering the change in the heat transfer area, and improving the control accuracy. Thus, the liquid surface position control device for the condenser 13 that reduces the consumption of excess heat energy during the reheating at 11 can be obtained.

  In addition, the change width of the heat transfer area can be maintained within an allowable range, and the switching operation of discharging the liquid phase working medium and replenishing supply can be provided with hysteresis, thereby reducing the frequency of the switching operation and condensing. As the operation of the vessel is stabilized, the durability of the device for discharging and replenishing is improved. Furthermore, since the discharge of the gas phase working medium (water vapor) is prevented while the liquid phase working medium (water) is discharged and the set liquid level is appropriately controlled, the operation of the condenser can be stabilized. In addition, the liquid phase working medium can be replenished and supplied to the set liquid level directly from the open reservoir for storing the liquid phase working medium via the return pump. The liquid level position can be stabilized accurately at an early stage by highly accurate supply amount control. Furthermore, it is possible to control the liquid level while maintaining the total mass flow rate of the working medium in the circuit, and it is configured as a circulation circuit that does not require the addition of a special device for discharging the working medium to the outside and replenishing from the outside. it can. Furthermore, it is possible to reduce the variation of the liquid level position for each cooling pipe of the condenser, and to stabilize the liquid level quickly and accurately at the time of draining and replenishing the liquid phase working medium, thereby stabilizing the operation of the condenser. It can be carried out.

  INDUSTRIAL APPLICABILITY The present invention is used as a relief valve device when a high pressure exceeding an allowable limit pressure such as an expander or an evaporator of a vehicle-mounted Rankine cycle device is generated.

It is a lineblock diagram showing the whole Rankine cycle device system concerning the present invention. It is a fragmentary sectional side view which shows the internal structure of the water supply pump unit which concerns on this embodiment. It is a figure which shows arrangement | positioning structure when the Rankine-cycle apparatus based on this invention is mounted in a vehicle. It is a graph which shows the time change of exhaust gas energy. It is a graph which shows the time change of target water supply amount. It is a graph which shows the time change of steam pressure. It is sectional drawing of the relief valve as a 2nd relief valve. It is a fragmentary sectional view of the bursting type safety valve as a 1st relief valve. It is a perspective view of the rupture disk of the rupture-type safety valve as a 1st relief valve. It is a system block diagram which shows the flow of the working medium of a Rankine cycle apparatus. It is a side view which shows the internal structure and peripheral device of the part of a condenser. It is sectional drawing which shows a structure when the air vent is closed. It is the sectional view on the AA line in FIG. It is sectional drawing which shows a structure when the air vent is open. It is a graph which shows the saturation curve of a thermo liquid and water. It is a figure for demonstrating the detail of a liquid level position setting. It is a flowchart which shows the operation | movement flow of the liquid level position control apparatus of a condenser. It is a timing chart which shows the change of the vehicle speed change of the vehicle carrying the Rankine-cycle apparatus based on this invention, an engine output change, the feed water flow volume to an evaporator, and the liquid level position of a condenser. It is the schematic diagram which showed the conventional vehicle-mounted Rankine-cycle apparatus simply.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rankine cycle apparatus 11 Evaporator 12 Expander 13 Condenser 14 Water supply pump unit 15 Piping 16 Piping 17 Piping 18 Piping 22 Safety valve 26 Piping 32 Open tank 37 Return pump 38 Liquid level sensor 39 Air vent 41 Sealed tank 42 Water corelesser 43 Motor 44 High-pressure feed pump 45 Exhaust pipe 46, 47, 48 Cooling fan 202 Relief valve 209 Flow restriction device (orifice)

Claims (5)

An evaporator that heats the liquid phase working medium by heat from a heat source to change the phase to a gas phase working medium;
An expander that converts thermal energy of the gas phase working medium discharged from the evaporator into mechanical energy;
A condenser that cools the gas phase working medium discharged from the expander and changes the phase to a liquid phase working medium;
In the Rankine cycle device provided with a supply pump that pressurizes the liquid-phase working medium discharged from the condenser and supplies it to the evaporator in a closed circuit,
During the closed circuit between the supply pump and the evaporator and in which the working medium is in a liquid phase state, the internal pressure in the closed circuit is set to be at least lower than the allowable limit pressure of the expander or the evaporator. A discharge valve device for discharging the working medium out of the closed circuit when the pressure is higher than the set limit pressure ,
The Rankine cycle device , wherein at least a part of the working medium discharged from the discharge valve device to the outside of the closed circuit is discharged around the heat source . The discharge valve device includes a plurality of discharge passages for leading the discharged working medium out of the closed circuit and discharging the working medium out of the closed circuit, and a flow restriction device is provided in at least a part of the discharge passage. Rankine cycle system according to claim 1 Symbol mounting characterized.   The Rankine cycle device according to claim 1, wherein the discharge valve device is disposed closer to the supply pump than at least the evaporator. An evaporator that heats the liquid phase working medium with heat from a heat source to change the phase to a gas phase working medium;
An expander that converts thermal energy of the gas phase working medium discharged from the evaporator into mechanical energy;
A condenser that cools the gas phase working medium discharged from the expander and changes the phase to a liquid phase working medium;
In the Rankine cycle device provided in a closed circuit with a supply pump that pressurizes the liquid-phase working medium discharged from the condenser and supplies it to the evaporator,
During the closed circuit between the supply pump and the evaporator and in which the working medium is in a liquid phase state, the internal pressure in the closed circuit is set to be at least lower than the allowable limit pressure of the expander or the evaporator. A discharge valve device that opens the closed circuit to the atmosphere and discharges the working medium in the circuit to the outside of the closed circuit when the pressure is higher than the set limit pressure. A Rankine cycle device, which is arranged close to the side. The discharge valve device includes a plurality of discharge passages for leading the discharged working medium out of the closed circuit and discharging the working medium out of the closed circuit, and a flow restriction device is provided in at least a part of the discharge passage. The Rankine cycle apparatus according to claim 4.

Images